There are three long-range goals of this research program: (1) The program of stage-specific synthesis of protein and of rRNA, 4S RNA, 5S RNA and mRNA during oogenesis will be determined, using high resolution RNA gel electrophoresis, and cell-free translation of mRNA. (2) Differential utilization of oocyte mRNA will be studied. Both quantitative and qualitative differences in the classes of mRNA used for protein synthesis in the oocyte and the mRNA selectively sequestered in the formation of the maternal mRNA program will be examined. mRNA from oocyte polysomes (engaged in protein synthesis) and from the subribosomal compartment (the site of maternal mRNA storage) will be compared by RNA gel electrophoresis and by cell-free translation. The temporal sequence of synthesis and utilization of particular identifiable maternal mRNAs (e.g. actin, tubulin and histone mRNAs) will be studied. (3) The question of selective, qualitative vs. non-selective, quantitative recruitment of maternal mRNA following fertilization will be investigated. The recruitment of specific maternal mRNAs from the subribosomal to the polysomal compartment following fertilization will be monitored, using the cell-free translation assay and by hybridization to cloned DNA probes specific for histone, actin and tubulin mRNAs.